Transformer frame



v J. F. PETERS TRANSFORMER FRAME Filed D0. 10 1919 John F p67? WITNE Es: I

ATTORNEY Patented July 29, 1924.

UNITED STATES JOHN F. PETERS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

'rRAnsFoRMER FRAME.

Application filed December 10, 1919. Serial No. 848,971.

T all whom it may concern: 7

Be it known that I, JOHN F. PETERs, a

citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny 6 and State of Pennsylvania, have invented a new and useful Improvement in Transformer Frames, of which the following is a specification.

My invention relates to stationary induction apparatus and it has for its object to provide means in combination with apparatus of the character designated for preventing the leakage flux therein from entering the framing of the apparatus. 7

In the accompanying drawing, Figure 1 illustrates the manner in which my invention is embodied in a transformer of the shell type; Fig. 2 is a view of a core type transformer, certain portions thereof being broken away to more clearly illustrate the manner in which my invention is embodied in apparatus of the latter character, and Figs. 3, '4 and 5 are fragmentary sectional views illustrating the damping means 'employed.

Inasmuch as the framing in stationary induction apparatus is at some point parallel. to the lines of magnetic flux which circulate through the magnetic circuits of the apparatus, these lines of flux tend to leak into the framing. As the transformers increase in size, the net magnetomotive force functioning in the frame attains a large value and is often sufiiciently efiective to abnormally heat the frame portions of the apparatus.

Heretofore utilized methods for preventing the flux from crowding out into the frames, such, for instance, as introducing air gaps in the frame, have proven inadequate in the larger units. Moreover, the provision of gaps in the frame members in order to preclude the establishment of a closed circuit for the leakage lines of flux often results in a weakened structure.

In order to overcome the obvious disadvantages of the heretofore practiced meth-- ods of preventing the leakage of the flux lines into the transformer frames, I proose to so associate damping means withthe frame members that the magnetic permeance of the frame is reduced to substantially zero. Moreover, I so associate the dampin means with the frame members that the maximum number of magnetic lines are embraced thereby,this specific arrangement of the damping means being instrumental in further enhancing the beneficial results attained with my invention. As will hereinafter appear, it is necessary to associate such means with only those portions of the frames which are subjected to the magnetic action.

Referring more particularly to the drawing, atransformer of the shell type is shown in Fig. 1 and comprises a core member 1 which is embraced by, and embraces, coil groups 2, 3 and 4, all of which are supported on pedestal legs 55. Horizontally extending girder members 66 and 7-7 serve to support the core structure in the direction of its longer dimension, while end girder members 8-8 and 9-9 support the same at its ends and are secured to the members 66 and 77.

From a consideration circuits of a transformer of the character described, it will be seen that the leakage lines of flux tend to crowd outwardly into the frame and there circulate, thus causing an abnormal heating of these members. In order to reduce the flow of magnetic flux in the framing, I dispose'thereabout, at advantageous points. short-circuited turns 10 of highly conducting material. In accordance with Lenzs law, currents will be set up therein in such a direction that the damping, action of the turns will substantially preclude the flow therethrough of lines of flux, it being lmown that it is almost impossible to cause flux to change through a short-circuited turn. It will be observed that I have positioned the turns 10 at such points that they will embrace the maximum number of lines of force, whereby their beneficial action is greatly enhanced.

Fig. 2 illustrates the manner in which my invention is embodied in a. transformer of the core type. The core member in this case comprises core legs 11 and 12 and yoke members 13-13 joining the same, only the upper one of the latter being shown in the illustration. The coil members 2 and 3 are associated with the core legs 11 and 12 respectively, the coil 3 being broken away in order to show the manner in which a stiffening member 14 is positioned to support the core legs in a vertical direction. It will be understood that a companion member is positioned at the rear of the core legs shown, and that the two members together consti- 11 of the magnetic tute a supporting structure for the leg memher. They are, however, separated from the core leg by layers of insulating material 15-15.

The girder members 66 and 7-7 are disposed along the yoke portions 13 and are secured together by frames 8 which are riveted thereto. The framing is further stiffened by the use of tie rods 16, the rod which is revealed by the breaking away of a portion of the coil 3 being the only one which is substantially visible, but it will be observed that these rods pass from the top framing to the bottom framing at each of the four corners of the two cruciform core legs 11 and 12, their position being indicated by the nuts which are used to increase the tension between the top and bottom framing.

Damping means 17 are associated with the girders 66 and 77 and are so positioned as to embrace the maximum number of lines of force, for the purpose set forth in connection with the showing of Fig 1. The leakage lines will also tend to crowd into the stiffening members 14, and I have, therefore, likewise provided that member with a short -circuited turn 18 of highly conducting material, it being'observed that this turn is passed around the stiffening member and c occupies the space which is formed by cutting away the mid-portion of the insulating layers 15 between the stiffening member and the core leg. This construction admits of a very advantageous and beneficial positioning of the stiffening-member damping means. An additional point of leakage line concentration exists. namely, the tie rods 16 and, as shown, I have wound thereabout short-circuited turns 19-19. The fragmentary sectional views. Figs. 3, 4 and 5. are self-explanatory and illustrate the manner in which the short-circuiting turns are wound about the various flux-receiving frame members. I

While I have illustrated the shell type transformer as being of a polyphase character and the core type transformer as having single-phase characteristics. it will be understood that my invention may be applied to stationary induction apparatus irrespective of the phase character thereof, since I have above pointed out the specific positioning which should be used in order to realize the maximum benefits in the application of my invention.

While I have illustrated but two embodiments of my invention, it will be apparent that many modifications may be made therein by those skilled in the art, and I desire, therefore, that it shall be limited only by the showing of the prior art or by the scope of the appended claims.

I claim as my invention:

1. In a stationary induct-ion apparatus, a core member, coils associated therewith,

framing for supporting said core member,

and means comprising a short-circuited coil in combination with said framing to maintain substantially Zero magnetization thereof.

2. In a stationary induction apparatus, a core member, coils associated therewith, framing for supporting said core member, and means in combination with said framing for reducing to substantially zero the magnetization thereof by stray magnetic flux.

3. In a stationary induction apparatus, a core member and coils associated therewith, magnetizable framing for supporting said core member, and damping means inductively associated with the framing for reducing to substantially zero the magnetization thereof.

4. In a stationary induction apparatus, a

core member and coils associated therewith,

magnetizable framing for supporting said core member, and damping means comprising short-circuited turns of conducting material inductively associated with the framing forreducing to substantially zero the magnetization thereof.

5. In a stationary induction apparatus, a core member and coils associated therewith, magnetizable framing for supporting said core member, and damping means comprising short-circuited turns of conducting material inductively associated with the framing for reducing to substantially zero the magnetization thereof, said turns being so positioned with respect to said framing as to embrace the maximiun number of magnetic lines of flux.

6. In a stationary induction apparatus, a core member comprising legs and yokes, coils associated therewith, magnetizable frames for supporting said core member comprising horizontally-extending girders for the yokes and vertically-extending stifieners for the legs, and damping means for reducing to substantially zero the magnetization of said girders and stifieners.

7. In a stationary induction apparatus, a core member comprising legs and yokes, coils associated therewith, magnet-izable frames for supporting said core member comprising horizontally-extending girders for the yokes, tension rods between said girders, vertically-extending stifieners for the legs, and damping means inductively associated with the girders, the stiffeners and the tension rods for reducing to substantially zero the magnetization of said girders and stiifeners. i I

8. In a stationary induction apparatus, a core member comprising legs and yokes, coils associated therewith, magnetizable frames for supporting said core member comprising horizontally-extending girders for the yokes, tension rods between said girders. vertically-extending stifleners for 10. An alternating-current electrical device the legs. and damping means comprising comprising a coil, a magnetizable member 15 short-circuited turns of conducting material associated therewith and subject to heating inductively associated with the girders, the by reason of stray magnetic flux therefrom, stifleners and the tension rods for reducing ofashort-circuited conductore-mbracingsaid to substantially zero the magnetization of member for substantially preventing the said girders and stitl'eners. heating of said member by preventing the 2 9. In combination with an alternatingpassage of flux therethrou h current electrical device having a mag- In testimony whereof, I have hereunto netizable portion subject to heating by stray subscribed my name this 25th day of Nomagnetic flux, of a short-circuited band vember 1919. around said portion for substantially preventing the passage of flux therethrough. JOHN F. PETERS. 

